(2-y)(4y-7)=0

Solution for (2-y)(4y-7)=0 equation:

(2-y)(4y-7)=0

We add all the numbers together, and all the variables

(-1y+2)(4y-7)=0

We multiply parentheses ..

(-4y^2+7y+8y-14)=0

We get rid of parentheses

-4y^2+7y+8y-14=0

We add all the numbers together, and all the variables

-4y^2+15y-14=0

a = -4; b = 15; c = -14;
Δ = b2-4ac
Δ = 152-4·(-4)·(-14)
Δ = 1
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1}=1$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-1}{2*-4}=\frac{-16}{-8}
=+2
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+1}{2*-4}=\frac{-14}{-8}
=1+3/4
$